Scaffold
npx create-inco-app@latest my-app --wallet rainbowkit --framework hardhat --chain evm --yes
Environment Setup
Get your WalletConnect project ID from cloud.walletconnect.com and add it to frontend/.env.local:
NEXT_PUBLIC_WALLETCONNECT_PROJECT_ID=your_project_id_here
NEXT_PUBLIC_CONFLOTTERY_ADDRESS=<deployed_contract_address>
Without a WalletConnect project ID, the app falls back to a basic wagmi config with injected wallets only (MetaMask, etc.).
Provider Setup
RainbowKit uses getDefaultConfig() for convenient setup when a WalletConnect project ID is available, and wraps the app with RainbowKitProvider for the connect modal UI.
"use client";
import { ReactNode, useState, useEffect } from "react";
import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
import { WagmiProvider, createConfig, http } from "wagmi";
import {
getDefaultConfig,
RainbowKitProvider,
darkTheme,
lightTheme,
} from "@rainbow-me/rainbowkit";
import { ThemeProvider, useTheme } from "next-themes";
import { baseSepolia } from "wagmi/chains";
const queryClient = new QueryClient();
const projectId = process.env.NEXT_PUBLIC_WALLETCONNECT_PROJECT_ID || "";
const config = projectId
? getDefaultConfig({
appName: "inco confidential lottery",
projectId,
chains: [baseSepolia],
ssr: true,
})
: createConfig({
chains: [baseSepolia],
transports: {
[baseSepolia.id]: http(),
},
ssr: true,
});
const RainbowKitWithTheme = ({ children }: { children: ReactNode }) => {
const { resolvedTheme } = useTheme();
const [mounted, setMounted] = useState(false);
useEffect(() => {
setMounted(true);
}, []);
const rainbowTheme =
mounted && resolvedTheme === "light"
? lightTheme({ accentColor: "#262626", accentColorForeground: "#fafafa", borderRadius: "none" })
: darkTheme({ accentColor: "#d4d4d4", accentColorForeground: "#0a0a0a", borderRadius: "none" });
return (
<RainbowKitProvider theme={rainbowTheme}>{children}</RainbowKitProvider>
);
};
const Providers = ({ children }: { children: ReactNode }) => {
return (
<ThemeProvider attribute="class" defaultTheme="dark" enableSystem>
<WagmiProvider config={config}>
<QueryClientProvider client={queryClient}>
<RainbowKitWithTheme>{children}</RainbowKitWithTheme>
</QueryClientProvider>
</WagmiProvider>
</ThemeProvider>
);
};
export { Providers };
Provider hierarchy: ThemeProvider → WagmiProvider → QueryClientProvider → RainbowKitProvider
RainbowKit sits on top of wagmi and provides a pre-built connect modal with wallet discovery. The RainbowKitWithTheme wrapper syncs the modal theme with your app’s dark/light mode.
Inco SDK Integration
The Inco SDK works with the walletClient provided by wagmi (which RainbowKit manages). Here’s the core pattern:
import { Lightning } from "@inco/js/lite";
import { handleTypes } from "@inco/js";
import { useAccount, useWalletClient, useWriteContract } from "wagmi";
import { parseEther } from "viem";
// Initialize Inco once
const zap = await Lightning.latest("testnet", 84532);
// Encrypt a value before sending on-chain
const { address } = useAccount();
const { data: walletClient } = useWalletClient();
async function deposit(amount: string) {
const ciphertext = await zap.encrypt(parseEther(amount), {
accountAddress: address,
dappAddress: LOTTERY_ADDRESS,
handleType: handleTypes.euint256,
});
const fee = await publicClient.readContract({
address: zap.executorAddress,
abi: getFeeAbi,
functionName: "getFee",
});
writeContract({
address: LOTTERY_ADDRESS,
abi: confLotteryAbi,
functionName: "deposit",
args: [ciphertext],
value: fee,
});
}
// Decrypt with attestation
async function checkWinner() {
const encryptedHandle = await publicClient.readContract({
address: LOTTERY_ADDRESS,
abi: confLotteryAbi,
functionName: "getMyWinnerCheck",
args: [currentRound],
account: address,
});
const result = await zap.attestedDecrypt(walletClient, [encryptedHandle]);
const isWinner = result[0].plaintext.value; // true or false
}
RainbowKit manages the wallet connection — once connected, wagmi’s useWalletClient() provides the signer that Inco’s attestedDecrypt uses for signing attestation requests.
Dependencies
| Package | Purpose |
|---|
@rainbow-me/rainbowkit | Wallet connect UI & management |
@inco/js | Inco encryption/decryption |
wagmi | EVM wallet hooks |
viem | Ethereum utilities |